Diffusion plate used in direct-type backlight module and method for making the same

Abstract

The present invention relates to a diffusion plate used in a direct-type backlight module and a method for making the same. At least one of the surfaces of the diffusion plate has a microstructure constituted by repeated undulation that can refract and diffuse the incident light beams that enter the diffusion plate. Therefore, the paths of the light beams after entering the diffusion plate are changed, which raises the luminance of the backlight module.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a diffusion plate used in a direct-type backlight module and a method for making the same, particularly to a diffusion plate having a microstructure on the illuminated surface thereof and a method for making the same. [0003] 2. Description of the Related Art [0004]FIG. 1 shows a schematic view of a conventional direct-type backlight module. The direct-type backlight module 1 is used in a liquid crystal display and comprises a diffusion plate 10, a plurality of lamps 12, a reflector 14, a diffusion film 16, a brightness enhancement film (BEF) 18 and a plurality of diffusion particles 19. [0005] The diffusion plate 10 is a transparent body doped with the diffusion particles 19 therein or thereon. The refractive index of the diffusion particles 19 is different from that of the body of the diffusion plate 10. The light beams in the diffusion plate 10 are diffused due to the refraction of...

AI Technical Summary

Benefits of technology

[0008] One objective of the present invention is to provide a diffusion plate used in a direct-type backlight module. At least one of the surfaces of the diffusion plate has a microstructure constituted by repeated undulation that can refract and diffuse the incident light beams that enter the diffusion plate. Therefore, the paths of the light beams after entering the diffusion plate are changed, which raises the luminance of the backlight module.

[0009] Another objective of the present invention is to provide a method for making a diffusion plate used in a direct-type backlight module. The method utilizes a corolling process to make a diffusion plate with composite structure and form a microstructure on the surface of the diffusion plate. Therefore, the paths of the light beams after entering the diffusion plate are changed, which raises the luminance of the backlight module.

[0010] Yet another objective of the present invention is to provide a method for making a diffusion plate used in a direct-type backlight module. The method utilizes rolling wheels to roll a material to form a diffusion plate with composite structure and form a microstructure on the surface of the diffusion plate. Therefore, the paths of the light beams after entering the diffusion plate are changed, which raises the luminance of the backlight module.

[0011] Still another objective of the present invention is to provide a diffusion plate used in a direct-type backlight module. The diffusion plate itself has the functions of conventional optical films, which can reduce the variable factors of parts and raise the reliability of the backlight module. Further, the cost of the backlight module is reduced due to the omission of the expensive conventional optical films.

Problems solved by technology

However, the optical defects easily occur on the optical films due to the environmental affect so that the yield of the backlight module 1 is lowered.

Additionally, the optical films are expensive, which raises the cost of the backlight module 1.

Further, each optical film only has a single optical function, which limits the optical design, and cannot be adapted for various customized designs.

Images